Train-control system



March 3, 1931. Q 5 BUSHNELL 1,794,584

TRAIN CONTROL SYSTEM Filed Jill 18, 1928 FIG. 1-

INVENTOR gharles 5. Bushnel I, Maw

his ATTORNEY Patented Mar. 3, 1931 UNITED STATES PATENT OFFICE CHARLES S. BUSHNELL, OF ROCHESTER, NEW YORK, ASSIGNOR TO GENERAL RAILWAY SIGNAL COMPANY, OF ROCHESTER, YORK TRAIN-CONT ROL SYSTEM Application filed July 18, 1928.

This invention relates in general to a train control system, and has more particular reference to a mercury governor for directional control and low speed or zero speed reset.

In train control systems, whether they be of the intermittent or the continuous type, it is desirable to have means for subjecting the train to automatic control when preceeding in the direction of traffic, whether the pilot or the tender be leading. Likewise, it is desirable to relieve the train from being subject to automatic control when proceeding against the normal direction of traffic, with either the pilot or the tender leading, since, in this latter case. a moments consideration shows that, with travel in this direction, on entering a block the train puts the signals against it self, so that it could not proceed if it were subject to automatic train control. 7

It is also desirable, in automatic train control systems, to penalize the engineer on failure to properly operate his train, by such a means as forcing him to perform a resetting operation. It is usual to require the engineer to bring the train to a stop, and to alight from the train to reset, after having incurred an automatic brake application. At times it is undesirable, or impossible, for the engineer to leave the engine, and hence it is desirable to provide an automatic reset which functions upon the train being brought to a low speed or a standsill.

With the above and other considerations in mind, it is proposed, in accordance with this invention, to provide a governor, driven at a speed proportional to that of the train and operating to subject the train to automatic train control when proceeding in the direction of traffic with either the pilot or tender leading, and to relieve it from such control when travelling against the traflic direction with either pilot or tender leading. The governor is also to be arranged to function as a low speed or zero speed (according to adjust ment) reset means, for restoring the train control parts to normal after the incurrence of an automatic brake application.

More specifically, it is proposed, in accordance with this invention, to provide a governor including a central chamber within which Serial No. 293,771.

is a gear pump operated at a speed proportional to the train speed and functioning to pump mercury or other electric conducting fluid into one or the other of two containers connected to the central chamber, to thereby break contact in a selective manner, for selectively cutting in the proper one of a plurality receiving means on the train. The governor is arranged to make contact at a low, or zero speed, in each of the said containers, to thereby close a series reset circuit and restore the parts to normal.

Further objects, purposes, and characteris tic features of the invention will appear as the description progresses, reference being had to the accompanying drawing, showing, solely by way of example, and not in any mannor in a limiting sense, two forms which the invention can assume. In the drawing Fig. 1 is a wholly diagrammatic view showingone form which the invention can assume, in connection with an intermittent automatic train control system.

Fig. 2 is a wholly diagrammatic view showing a second form which the invention can assume, in connection with a continuous automatic train control system.

Referring now to the drawing, and first to Fig. 1, there is shown herein one form of applicants governor used in connection with an intermittent train control system.

The governor proper comprises a. casing, with the cover, (not shown) removed, having a central body portion 1, and forward and rearward upstanding leg portions 2 and 3, these portions all being hollow and interconnected by passages at and 5, and partly filed with an electrically conducting iinid 6, such as mercury or the like. Within the body portion 1, is a gear pump comprising a driving gear 7, and a driven gear 8, the driving gear 7 being connected to be driven by a car axle, as indicated by the dot and dash line 9, whereby to drive the pump in one direction or the other, as indicated by the arrows F and B, according as the. car travels in the direction of traflic as indicated by the arrow 10, with the pilot or the tender respectively leading.

The mercury 6 in the governor is arranged and lasts relays ER and BE, by

to make contact with electrodes 11 and 12 PI'OJGClElIlg into the legs 2 and 3, and connected thereto, but insulated therefrom, by caps and nuts 13 and 1 1.

When the train is stationary, the gear pump likewise is stationary, and the iner cury 6 makes contact with both of the electrodes 11 and 12. On the other hand, when the pump is operated, as in direction of the Y arrow F, the mercury is pumped into the leg 3 and out of the leg 2, whereby to break contact between the mercury and the electrode 11. On reverse operation of the gear pump, contact is broken between the mercury and electrode 12,

Connected respectively tothe electrodes 11 i I means of wires 15; and 16] respectively.

In order to simplify he eiiplanation of this invention, a usual convention 1s employed of using the letters B and G to denote oppos1 poie'soi": a source or sources of electrical I through electrode 12 controls"energiiiation of relay BR. It is thus clear that wit-hierward operation of the gear pump, contact between electrode 11 and mercury 6 is broken so that elayFR is de energized, and with backward operation of the gear pump, contact with electrode 12 is broken and'relay BB is deenergized.

Show'n in Fig. 1 is a stretch of track constituted bytra'ck rails 21, separated into elect'rically insulated blocks by means of insulating joints 22, a. car being represented, by means of uheels and axles 23, on the trunk rails.

Carried by the car is receiving apparatus including. a receiver positioned on the right hand side of the car, and a receiver R positioned at the left hand side of the car. Each receiver R, R includes a core 2 1, 2 1 of magnetic material and laminated, if 'desired, to minimize losses, a primary winding 1 P and a secondary winding S, S respectively.

Each receiver R, R is adapted to cooperate with trackway means including track'way inductors in a usual manner, such, for example, as shown in Patent 1,619,698 of March 1,

1927, to C. S. Bushnell, and for further n planation in this reference should be had to such patent. v

The system of Fig. 1 also includes aniain relay MR, having contact fingers and 26,

tact finger 27;

mally closed, together with means, the spring 29 and dash pot 3 0 or the like, for causing the Contact linger 28to open a predetermined time after operation oi? the acknowled ing contactor and the consequent closing of con-- tact fin 'er 28'can be varied at will and can, b v .7 7 7 for eizam le. be an ,roximatei 15 seconds. 1 J

The system also includes a device EPV, which is normally energized and operates, when 'de-enler ized, to exert a. train controlling influence such as a brake application, by any known or desired means, such for example as directly venting'theusual brake pipe, operating the engineefis brake valve through an actuating device; operatin a separate brake application device, etc.

The various parts in Fig. 1 are shown in the positio s and conditions existing when the train is at standstill The governor gear pu' p is stationary, and the'two directional control relays BR and FR are energized to thereby energize 'rela y MR through a circuit including the twoconta-ct fingers 19 and 17 and front points of the respective relays BR and FR, wire'31 and the winding of relay MB. The acknowledging contactor is in its normal raised position to hold contact finger 27 open and contact finger28 closed, and this, together with the en'ergization of relay MR,

completes a circuit for the energization of the device EPV,wli.icli can, be tracedirom one terminal C of a source of energy, winding P wire 32, winding 1?, wire 38, EPV, wire 3 1, contact finger 28 and front point of A070, wire c'ontact finger 26 and front point of relay MB, to an opposite terminal B of a source of energy. lVith the device EPV energized the train is unrestricted and is free to start.

For a ready understanding of the operation of the parts shown in Fig. 1 and above described, assume the train, with its pilot leading, is started in the direction of traific as indicated by the arrow 10. Upon operation of the gear pump in the forward direction, F, at least part or" the mercury 6 is pumped out of the leg 2 and into the leg 8, to thereby break the energizing circuit, above indicated, for the forward relay FR. This circuit is broken either immediately upon the starting of the train or upon the train reaching a predetermined speed, this all depending upon the positioning and proportioning or" parts, and the quantity of conducting fluid, in the governor. De-energization of the ion ward relay FR, breaks theholding circuit for relay MR, at contact finger 17, but makes a second energizing circuit for such relay at contactfinger 18 and back point of FR, which circuit includes, the secondary winding S of receiver R, wire .36, 'ceatac finger 18 and back point or relay FR, wire 39, relay MR, wir

The retarded action on con 37, and contact finger 25 and front point of relay MR. Contacts 17 and 18, and 19 and 20 are arranged to make before break, to avoid momentary de-energization of relay MR. This circuit, it should be noted, is a stick circuit which if once broken, must be specially restored. With relay MR energized, the control device EPV is energized through the circuit traced above, and the train is free to proceed.

On passing a wayside inductor in its inactive or choked condition (see Patent 1,619,698 referred to above) no effect is produced on the control apparatus, and the train can proceed as before.

Upon the car-carried receiver R passing in'inductive relation over an active or un choked wayside inductor, a surge of flux is produced by the winding P, to induce a volt age in the secondary winding S is such a direction as to momentarily de-energize relay MR, thus to cause such relay to release its contact fing rs. Release of contact linger 25 breaks the stick circuit for MR referred to above, and of contact finger 26 breaks the energizing circuit for EPV which latter, upon being de-energized, applies the brakes or exerts any other desired control influence.

If the engineer, however, be alert, and anticipates the above recited operation, and depresses the acknowledging contactor Ac]: eefore relay MR becomes de-energized as above described, energy is placed on relay MR to retain it energized even though the r normal holding circuit through the secondary winding S of the receiver R be broken. This acknowledging circuit includes contact finger 27 and back point of A071: wires 38 and 39, relay MR, wire 37 and. contact finger 25 and front point of relay MR. Upon passing beyond the wayside induct-or referred to, contactor A070 can be released, since the normal holding circuit for main relay MR is then again re-energized. In this manner, by properly acknowledging, an automatic brake application can be avoided or forestalled.

Assuming however that no acknowledging act be performed, and an automatic brake application be incurred, there is no way of reiieving the train from such brake application other than bringing it to a stop or to a predetermined low speed whereupon the gear pump of the governor is slowed down sufficiently to re-establish the energizing circuit through relay FR to thereby complete the pick-up circuit for relay MR which, as pointed out above, includes the contact fingers 19 and 17 and their front points, in series, of relays BR- and FR. This operates to restore or reset the apparatus.

If the locomotive be operated in the direction of traflic with the tender leading, the gear pump will operate in the direction of the arrow B, to thereby break contact between the mercury 6 and the electrode 12, so as to ened.

de-energize relay BR and cut into operation the car-carried receiver R This receiver It, now being on the side of the track that was formerly occupied by the receive R, will cooperate with the wayside inductors in the manner described above, to control the train in the described manner.

Should the train be operated in a direction opposite to the normal flow of traliic, with either the pilot or tender leading, the governor will operate to cut into action that receiver which does not pass over the wayside inductors, which latter are positioned along but one side, the right side, of the trackway, and hence the train is relieved from auto matic control. In this manner the desired result set forth in the introductory portion of this specification is attained.

From the above it is seen that applicants governor operates to selectively control the cutting into, or out of operation, of the automatic train control system, and to function as either a low speed or a zero speed automatic reset means.

It is obvious that the parts can be so positioned, or the amount of mercury or other conducting fluid in the governor be so proportioned, or both, that contact will be broken between one of the electrodes and the mercury at practically zero speed, or at any higher speed desired such, for example, as two miles per hour, or the like.

It is also contemplated by this invention to arrange the governor in any other desired or obvious manner to perform its above described functions. As an example of one of the many adaptations of which it is susceptible, the electrodes 11 and 12 could be shortor a certain amount of the mercury 6 removed from the governor, so that at standstill, contact is broken, instead of made, between each electrode and the mercury, and on operation of the pump, contact is made with one only of the electrodes instead of, as at present, broken at one of the electrodes. WVith such an arrangement in the governor, the contact fingers and fixed contacts of relays FR and RR would be reversed so that the reset circuit for the main relay would pass through back points instead of front points, and the holding circuits for the main relay would pass through front points instead of, as at present, through hack points.

Referring now to Fig. 2, there is herein shown a second application of the invention, involving a continuous train control system employing double ended equipment.

As in Fig. 1, the governor is arranged to control two relays BR and FR, to thereby selectively control the train control system. In this form of invention, the device EPV in cludes a stick contact 40, the main relay MR- has but a single winding instead of a double winding as in Fig. 1, and in place of an acknowledging contactor there is here employed i a speed controlled contact arm SA, which assumes a position depending on the speed of the train, as-indicated by the dot and dash line 41 connecting-the arm to'the car axle 23, an ordinaryfly ball speed governoror the like being employed; The speed arm SA, in its movement, wipes over fixed contact segments 42 and 43, contact being broken with 42 at a speed above 60 miles per hour, for

example, and with contact43 at a speed above miles per hour, forexainple. r

r In thiscontinu-ous form oftrain control apparatus the track rails 21 are supplied with alternating train control'curren't from a track transformer T, and in place of the receivers being positioned at each side of the car, there are receiving coils RC and RC the first positioned in front'of the front axle, and the second positioned to the rear of the rear-most axle, of the engine and tender, respectively and of course, inductively related to the track rails; V

The receiving coils RC and RC cooperate with the track rails and the train control current and trackway apparatus in the manner set forth, for example, in ?atent 1,703,844 granted Februar 26, 1929, to William D. Hailes,to which reference should be made for further information in this par ticular.

The various parts, in the form of invention shown in Fig. 2, are shown in the positions and conditions corresponding to the train at a standstill. The governor pump is stationary, the relays Blt'an'd FR are energized to thereby cut out both of the receiving coils RC and RC by contact fingers 18 and 0t relays FR and BE, and to complete a holding circuit for energizing EPV which includes contact fingers 19 and 17 and front points of relays BR and FR respectively, wires 44 and 45, EPV wires 46 and 47, stationary speed contact 43 and arm SA.

irssuming now tl at the train is started in the direction of the arrow 10, with the pilot leading, the governor pump is rotated at a speed corresponding to that of the train in the direction of arrow F, to thereby de-energi'ze the relay FR in a manner similar to that described in connection with Fig. 1. This breaks the holding circuit for EPV passing through contact finger 17 in raised position, as described above, but closes an energizing circuit for main relay MR at contact finger 1 8 and back point of relay FR which circuit includes, the receiving coils RC, wire 51, contact finger 18 and back point of relay FR, relay MR, and wires 52 and 53 back to RC. .Vith relay MR energized a stick circuit for EPV is completed which includes stick contact in raised position, EPV contact finger 49 and front point of relay MR and speed arm SA. It should be noted that below a speed of the assumed 15 miles-per hour, the speed arm SA makes contact with the fixed contact 43, so that the depears that on starting the train, as described,

the receiving coils RC are cut into circuit to control relay MR and that this control while effective, is not governing, until the speed of the train exceeds the assumed 15 miles-per hour, as below this speed the device EPV is energized even though relay MR be deenergized. Above a speed of 15 miles per hour, however, the stick energizingcircuit for EPV which passes through fixed speed contact 43 is broken, so that it is necessary to have relayMR energized to maintain EPV energized.

A maximum speed limit is set up by the fixed speed contact 42, since, if the train eX- ceed the assumed maximum speed of miles per hour, speed arm SA breaks contact with fixed contact 42 and thus de-energizes'EPV with a resultant automatic brake application.

So long as the receiving coils RC have voltages induced therein due to train control current in the track rails and relay FR is down, the main relay MR is energized and the train is free to proceed without restriclimit. Also, even though train control current be removed from the track rails by traffic controlled wayside means, such as shown in the above referred to Patent 1,703,844, with the resultant de-energization of main relay MR the train is free to proceed unrestricted if it keeps within the 15 mile per hour limit.

'Assume, however, that under danger conditions, that is, under conditions where the receiving coils RC are deprived of induced voltz-ige; if the train is running at a speed above 15 miles per hour, both of the stick circuits traced above for the device E'PV are broken, the device ElBV is Clo-energized, and an automatic brake application is incurred.

It is now necessary, in order to relieve the train of'the automatic brake application, to bring it to a full stop, or to a predetermined low reset speed, at which contact is again made between electrode 11 and the mercury 6, to thereby pick up relay FE and re-energize EPV through the energizing circuit including in series contact fingers 19 and 17 and front points of relays BR and FR, wires 44 and 45, EPV wires 46 and 47, contact 43 and speed arm SA. Thus, to reset train control apparatus after having incurred an automatic brake application, it is necessary to bring the train to a stop, or to a. predetei mined low reset speed, whereupon the governor of this invention operates to automatically reset the train control apparatus.

It should be noted that after having incurred an automaticv brake application it is 'tion it it keeps within the 60'mile per hour not sufiicient to merely bring the speed of the train within the 15 mile per hour limit, since the stick circuits for EPV when once broken, can of course not be again made until the device EPV is especially re-energized.

If the locomotive and tender be reversed so as to travel in the direction of tratlic with the tender leading, the governor pump operates in the direction of the arrow B, to thereby de-encrgizac relay BR and cut into operation the receiving coils BC. The operation.

is otherwise exactly the same as nst de scribed with regard to the receiving coils RC, as is likewise the reset operation.

lVith the train proceeding against the direction of traffic, with either the pilot or tender leading,the rearward, rather than the forward, receiving coils are cut into circuit and hence such receiving coils are ineffective to exert any control since they are blanked off or shunted out from train control current in the track rails by the intervening car axles 23. Thus the relay MR is de-energized and the train can proceed only at a speed within the assumed 15 miles per hour speed limit.

Thus, with the form of invention shown in Fig. 2, the governor effects the desired control. by selectively cutting into action the proper receiving coils, and by operating to reset, after the occurrence of an automatic brake application, at either a predetermined low speed or at zero speed.

Here again the governor could be arranged to make one contact when the pump is operated, instead of breaking one contact as just described, and the relays BR- and FR could have their contact fingers and front and back points reversed, all as described, more or less in detail, in connection with Fig. 1.

In connection with both forms of invention above described, the directional control governor and reset operates to subject the train to automatic train control when the train is moving in the direction of traflic with either the pilot or the tender leading, and to relieve it from such automatic train control when moving in a direction opposite to the normal direction of traffic with either the pilot or tender leading.

In the intermittent form of Fig. 1, when the train is not subject to automatic train control, it can proceed without any restriction so far as the automatic train control ap paratus is concerned.

In the continuous form of the invention as shown in Fig. 2, when the train is not subject to automatic train control, that is, when the train is travelling against the normal direction of tralfic, the train can proceed only within the speed limit set up by the low speed contact 43, since, if it proceed above this speed, the device EPV becomes de-energized because the three energizing circuits for EPV are then broken, these three circuits being one through the two front points of relays BR and FR, one through the stick contact 40 and speed contact 43, and one through the stick contact 40, contact finger and front point of relay MR and speed contact 42.

The above rather specific description of two forms which applicants invention can assume, has been given solely way of illustration, and is not intended, in any manner whatsoever, in a limiting sense. Obviously, the invention can assume various different physical forms, and is susceptible of numerous modifications, and all such forms and modifications, are intended to be covered by this application, come within the scope of the appended claims.

Having described my invention, I now claim 1. A directional control and reset governor, comprising, a hollow casing having a chamber and a plurality of arms, a contact projecting into, and electrically insulated from, each arm, an electrically conducting liquid in said casing, and pump means in said chamber for variably positioning said liquid relative to said contacts in accordance with the speed and direction of operation of said pump means, to thereby selectively control contact between said liquid and said contacts.

2. A governor for train control systems, comprising, a casing having a central chamber and forward and rearward upstanding legs, a contact projecting into, and electrically insulated from, each leg, electrically conductive liquid in said chamber and legs, and a pump in said chamber arranged to be driven in speed and direction in accordance with the speed and direction of motion of a train, to thereby selectively control contact between said contacts and said liquid.

3. A governor for train control systems, comprising, a casing having a central chamber and forward and rearward upstanding legs, a contact projecting into, and electrically insulated from, each leg, electrically conductive liquid in said chamber and legs, a pump in said chamber arranged to be driven in speed and direction in accordance with the speed and direction of motion of a train, to thereby selectively control contact between said contacts and said liquid, and a plurality of car-carried receiving means selectively cut into action by said contacts.

4. In a train control system, in combination, brake applying means initiated on deenergization, car-carried receviers respon. sive to traflic conditions and operable, when cut into action, to control said brake applying means, and a centrifugal pump operable to selectively cut into action said receivers in accordance with the direction of rotation of the car axles and to remove said brake applying means from under control of the selected receiver at a given low speed of said car and at the same time maintained said brake applying means energized,

5. In a train control system, in combination, brake applying means initiated on deenergization, car-carried receivers responsive to traffic conditions and operable, When out into action, to control said brake applying means, and a centrifugally operated mercury device driven from a'car axle and operable to selectively complete circuits to thus cut into action said receivers in accordance with the speed and direction of rotation of the car axles and to .remove said brake applying means from under control of theselected receiver, at a given loW speed of said car by opening circuits, and at the same time maintain said brake applying means energized.

6. In a train control system, in combination, a brake applying device, a plurality of receiving means responsive totrack'way conditions, and a single centrifugal pump, which is responsive to speed and direction, for placing said brake applying device subject to control by a receiving means dependent upon the direction oi. travel of the train, and for relievin g said brake applying device from such control at a predetermined low speed'ofthe train. 7 c I 7. In a train control system, in combination, a brake applying device initiated when de-energized, a plurality of receiving means responsive, to trackvvay conditions and positioned for, operation respectively during operating of the train in the direction of traflic with pilot and tender leading, and a speed responsive device operated from a car axle for puttinga particular receiving means into circuit for controlling said brake applying device dependent upon the direction of rotation of the car axles and for maintaining said brake applying device energized regardless of said receiving means at a predetermined low speed of the train.

8. In a train control system, in combination, a plurality of car-carried. receiving means arranged tobe responsive, respectively, to t-rackway co-nditionsdcpendent upon the'direction of travel, a brake apply-ing device, a separate cut-in relay for each said receivingmeans for completing circuit for placing said brake device under control of its receiving means, a fluid speed responsive directional governor and reset member driven from the "car axle and selectively controlling energizing circuits for said out in relays .dependent upon its direction of drive, and a cir cuit for controlling said brake device inde relays at a predetermined low speed of the train.

10. Ina train control system, in combinameans arranged to be responsive, respectively, to trackivay conditions dependent upon the direction of travel, a brake applying device, a cut-in relay for each said receiving tion, a plurality or car-carried receiving means for placing said brake deviceunder control of its receiving means, a speed responsive directional governor and reset member driven from the car axle and selectively con trolling said cut-in relays dependent upon its direction of drive, and a circu it for controlling said brake device independently of said receiving means and closed by said reset mem her acting through all of said cut-in relays" at zero train speed. I

In testnnony whereof I aflix my signature.

CHARLES vS. BUSHNELL.

pendently of said receiving meansand closed by said reset member at a predetermined loW speed of the train.

9. In a train control system, in combination, a plurality of car-carried receiving means arranged to be responsive, respective- 'ly, to trackivay conditions dependent upon the direction of travel, a bralte'applyingdevice, a cut-1n relay for reachsald receivmg means for placing said brake device under 

